9-beta-d-ribofuranosyl-7-deazapurine 5&#39;-phosphate esters



United States Patent 3,336,289 9-j8-D-RIBOFURANOSYL-7-DEAZAPURINE'-PHOSPHATE ESTERS William J. Wechter and Arthur R. Hanze, Kalamazoo,Mich., assignors to The Upjohn Company, Kalamazoo,

Mich., a corporation of Delaware No Drawing. ,Filed Sept. 20, 1965, Ser.No. 488,779 9 Claims. (Cl. 260-2115) The present invention is concernedwith novel compounds and, more particularly, with novel alkyl,cycloalkyl and aryl esters of 9-/8-D-ribofuranosyl-7-deazapurine5'-phosphates, intermediates thereto and a process of productionthereof.

The novel compounds and the generic process of produotion thereof can beillustratively represented by the following formulae:

wherein R and R are alkyl radicals having from 1 to 4 carbon atoms,inclusive, or together can form an alkylene chain of 4 to 6 carbonatoms, inclusive; wherein Z is selected fromthe group consisting ofhydrogen, hydroxy, amino, acylamino, in which the acyl group is of ahydrocarbon carboxylic acid containing from 2 to 12 carbon atoms,inclusive, and auisoyl, thio, and alkylthio in which the alkyl isdefined as above, and wherein R is selected from the group consisting ofalkyl radicals having'from 1 to 12 carbon atoms, inclusive, cycloalkylhaving from S to 10 carbon atoms, inclusive, and aryl having from 6 to12 carbon atoms, inclusive.

Alkyl groups having from 1 to 12 carbon atoms, inclusive, as hereinused, include, illustratively, methyl, ethyl, propyl, isopropyl, butyl,isobutyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl,and the like.

Cycoalkyl as herein use-d include cyclopentyl, cyclohexy-l,methylcyclopentyl, cycloheptyl, dimethylcyclohexyl, cyclooctyl,cyclodecyl and the like.

Aryl groups containing from 6 to 12 carbon atoms, inclusive, as hereinused, include, illustratively, phenyl, alkylsubstituted phenyls, e.-g.,methyl, ethyl, propyl, butylphenyls, a-na-phthyl, B-naphthyl, andalkylsubstituted naphthyls, e..g., methyl-, dirnethyl-, ethyl-,diethyl-substituted naphthyls, nitro-substituted phenyls, e.g.,p-nitrophenyl, 2,4 dinitrophenyl; nitro substituted naphthyl groups,e.g., Z-nitronaphthyl, and the like.

3,336,289 Patented Aug. 15, 1967 The process of the present inventionincludes: treating a 9 (2',3 O isopropylidene B D ribofuranosyl)-7-deazapurine 5'-phosphate (I) under anhydrous conditions with a reagentselected from alkanol; having from 1 to 12 carbon atoms, inclusive,cycloalkanols having from 5 to 10 carbon atoms, inclusive, phenols andnaphthol, having from 6 to 12 carbon atoms, inclusive, in the pres enceof a strong organic basic agent such as a trialkylamine and a condensingagent, e.g. dicyclohexylcarbodiirnide to give the corresponding alkyl,cycloalkyl or aryl ester of9-(2',3-O-isopropylidene-5-D-ribofuranosyl)-7- deazapurine 5'-phosphate,which is then treated with an acid to give the 'alkyl, cycloalkyl oraryl ester of 9-13-D- ribofuranosyl-7-deazapurine 5-phosphate. (II) Ifthe group Z is an acylamino group a base hydrolysis may precede orfollow the acid hydrolysis to obtain a compound II with a free aminogroup.

The novel alkyl, cycloalkyl and a-ryl esters of 9- 9-D-ribofuranosyl-7-deazapurine 5' phosphate (II) exhibit significantcytotoxic activity in vitro, particularly against the different types ofHerpes, Coe, and vaccinia viruses. For this reason the products can beemployed for cleaning glassware and instruments, used in the growing oftissue cultures in virus and tumor research, washing excised tumortissue, intended for transplant into animals, to inhibit the growth ofany KB tumor cells that might otherwise seed surrounding tissues or betransported to other parts of the animal body. The antriviral activitycan also be used to prep-are cultures of microorganisms free of viralphages, e.g., phage-free, antibiotic-producing Streptomyces cultures.The compounds moreover differ from the unesterified phosphates by beingretained in the blood senun, and not in the blood cells. This propertyis highly desirable from a toxicity stand point of view. Methyl 9-8-D-ribofuranosyl-7-deazaadenine 5'-phosph-ate is also active againstcertain fungi, such as penicillium, oxalicum.

The starting materials of Formula I are prepared as shown in thePreparations.

In carrying out the process of the present invention a selected startingmaterial of Formula I in an appropriate solvent selected from the groupof solvents consisting of py-ridines, picolines, lutidines,ethylpyridines, and the like is reacted, under completely anhydrousconditions, in the.

presenoeof a condensing agent such as a dialkylcarbodiimide,dicycloalkylcarbo-diimide, or the like with a se-.

lected alkanol, phenol or naphthol. All reagents must be completely dry,which is generally achieved by concentraiting a solution of the startingmaterial, a 9-(2',3-O-isopropylidene-[3-D-ribofuranosyl -7-deazapurine-S -yl phosphate, in the selected solvent, preferablypyridineunder reduced pressure. This procedure is usually carried outseveral times prior to adding the anhydrous alkanol or phenol and theanhydrous trialkylamine and condensing agent. The alkanol or phenolwhich is used to produce the ester of Formula II, is generally given ina large excess such as in 10 to 50 times the required molar equivalent.The organic base, a trialkylamine, is given in a quantity between one tofive times molar equivalent and the condensing agent in a quantity of 1to 30 times molar equivalent. The amounts are not critical and larger orsmaller amounts can be used.

The reaction period is generally between 4 hours and about 4 days. Atthe termination of the reaction, the

product, an alkyl or aryl 9-(2,3'-O-isopropylidene-fi-D-ribofuranosyl)-7-deazapurine-5-phosphate is recovered by conventionalmethods such as by washing the solution with ether and decanting theether, treating the remainder with water to destroy the carbodiimide(giving a substituted urea, which is removable by filtration) andconcentrating the solution. The concentrated solution is hydrolyzed toeliminate the isopropylidene moiety. The hydrolysis is carried out witha mineral organic acid, preferably with 80% aqueous acetic acid. If anacylamino group is to be eliminated, a base hydrolysis is necessary,preferably the base hydrolysis is carried out with concentrated ammoniumhydroxide in a lower alkanol such as methanol, ethanol, propanol,isopropanol and the like, at a low temperature, but for a long duration,e.g., at about room temperature (20 to 28 C.) and during a period of 10to 30 hours. In this manner the desired product is obtained withouthydrolysis of the ester moiety of the ribofuranosyl-7-deazapurine alkylor aryl phosphate esters. After the hydrolyses are completed, theproduct is isolated in conventional manner such as by crystallization,chromatography, extraction, electrophoresis and the like. The followingpreparations and examples are illustrative of the product and processesof the present invention, but are not to be construed as limiting.

PREPARATION 1 N -benzyl-9-(2,3-Ois0propylidene ,8 Dribofuranosyl)-7-deazaadenine [0r N -belzz0yl-9-(2,3-0-is0pr0-pylidene-p-D-ribofuranosyl)-6-amino-7-deazapurine; or N benzoyl 2',3 Oisopropylidene sparsomycin A; or N-benz0yl-2',3'-O-is0pr0pylia'enetubercidin] A. PRODUCTION or'SPARSOMYCIN A (TUBERCIDIN) BY FERMENTATION A soil slant of Streptomycessparsogeizs var. sparsogenes, NRRL 2940, was used to inoculate a seriesof 500-ml. Erlenmeyer flasks each containing 100 m1. of seed mediumconsisting of the following ingredients:

Glucose monohydrate g 25 Pharmamedia 1 g 25 Tap water q.s l 1Pharrnamedia is an industrial grade of cottonseed flour produced byTraders Oil Mill 00., Fort Worth, Tex.

The seed medium presterilization pH was 7.2. The seed was grown for twodays at 28 C. on a Gump rotary shaker operating at 250 rpm.

One shake flask of the seed described above (100 ml.) was used toinoculate a 20 liter seed tank containing 15 1. of the above sterileseed medium (S-l) plus 1 ml./l. of lard oil. The seed tank was grown for24 hours at a temperature of 28 C., aeration rate of 10 standard1./min., and agitated at a rate of 400 r.p.m.

' The seed tank, described above, was then used to inoculate a 380-1.fermentor containing 250 l. of the following sterile medium:

Glucose monohydrate g./l 10 Dextrin g./l 15 Pharmamedia g./l 20 WilsonsPeptone Liquor No. 159 1 g./l Lard oil ml./1 2 Tap water Balance WilsonsPeptone Liquor .No. 159 is a preparation of hydrolyzed proteins fromanimal origin.

The fermentation then proceeded for 113 hours during which time thetemperature was controlled at 28 C., filtered air supplied at a rate of100 standard l./minute, and agitation at 28 rpm. During the course ofthe fermentation, 1850 ml. of lard oil was added as an antifoam.

B. RECOVERY OF SPARSOMYCIN A The whole beer from the above fermentationwas adjusted from the harvested pH of 7.1 to pH 2.4 with 350 ml. ofsulfuric acid (concentrated) and filtered using 3.6%

diatomaceous earth as filter aid. The filter cake was washed with 0.2volume of deionized water, the clear beer plus wash (vol. 280 l.) wasadjusted to pH 7.35 with 300 ml. of 50% aqueous sodium hydroxide andallowed to stand overnight at 10 C. The clear beer was then adjusted topH 8 with 50 ml. of 50% aqueous sodium hydroxide and stirred for 1 hourwith 1% decolorizing carbon and 3% diatomite. The mixture was filteredand the carbon cake washed with 0.2 volume of 20% aqueous acetone. Thewashed carbon cake was eluted twice with 0.4 volume of 50% aqueousacetone, acidified to pH 2.5 with concentrated sulfuric acid, and theeluates pooled. The pooled acetone eluate (72 l.) was adjusted to pH 6.4with 30 ml. of 50% aqueous sodium hydroxide and concentrated to anaqueous solution (40 1.). The concentrate was adjusted to pH 5.9 andfreeze-dried to give 447 g. of lyophilized material.

An additional 1126 g. was obtained by twice repeating the abovefermentation and recovery. The combined lyophilized material (1573 g.)was slurried in 101. of methanol at 40 C. for 1 hour. Insoluble materialwas filtered off and Washed 3 times with 500 ml. of warm methanol (40C.). The methanol extracts and washes were combined (11.5 1.) andconcentrated in vacuo to a dry preparation weighing 321 g. (HRV25.3) andassaying 1.25 Proteus vulgaris biounits/mg.

C. PURIFICATION OF 'SPARSOMYCIN A Partition column.300 g. of the abovepreparation (HRV25.3) was placed in a partition column which wasprepared and developed in the following manner. A solvent system wasmade using equal volumes (350 l.) of McIlvaines pH 6.0 buffer and methylethyl ketone. A slurry containing 9.6 kg. of diatomite in 60 l. of upperphase and 4.8 l. of lower phase of the above-described solvent systemwas poured into a 12" column and packed with 4 p.s.i.g. of nitrogen. Thecolumn feed was dissolved in 3 l. of lower phase, slurried with 1920 g.of diatomite and enough upper phase added to make it mobile. The feedwas carefully added to the top of the column bed which was covered witha layer of sea sand. The column was eluted with upper phase solvent at arate of 2 l./minute. 4-1. fractions were collected except at thebeginning and end of the column when 20-1. fractions were collected. Thefractions were concentrated and bio-activities observed on P. vulgar-istrays. At this point in the process the separation of sparsomycin andsparsomycin A was effectuated. Further processing purified thesecomponents and ultimately resulted in crystalline material.

Fractions 24-34, inclusive, from the above partition column containedthe sparsomycin (9-B-D-ribofuranosyl- 7-deazaadenine) component.

Purification of sparsomycin A.The sparsomycin A component was purifiedand crystallized in the following manner. Fractions 11-20, inclusive,from the previously described partition column-part C-cont-ained thesparsomycin A component. These fractions were pooled and concentratedunder reduced pressure and 7.2 g. of crystalline material was isolated.These crystals were dissolved in 40 ml. of water and 50 ml. of 0.1 NHCl. The solution was heated gently to facilitate dissolving and thenfiltered. The clear solution was adjusted to pH 9.0 with 50% aqueoussodium hydroxide and chilled in the refrigerator for 5 hours. Thecrystals were collected by filtration, washed with water, and dried togive 5.65 g. of preparation ADA-102.1. 2 g. of this preparation werethen dissolved in 75 ml. of water and 20 ml. of 0.1 N HCl. This clearsolution was adjusted to pH 9.0 with 50% aqueous sodium hydroxide.Crystallization started immediately. The solution was left at 25 C. for7 hours and then the crystals were collected, washed with 25 ml. ofwater, and dried to yield 1.52 g. of preparation ADA- 105.1 having amelting point of 247.8-250 C., an optical rotation -62 (c.=0.718 in 0.1N HCl), an equivalent weight of 269, pKa' of 5.07 in water, anultraviolet absorption spectrum in Water 270 m a=44.14.

0.01 NH SO 227 111,14, a=85,28,

271 mp, a=40.82.

0.01 NKOH 270 m a=43.50.

a chanacteristic IR absorption at the following frequencies expressed inreciprocal centimeters:

3350 s 1160 (W) 3250 s 1134 (M) 3145 s 1120 (M) 3095 s (sh) 1093 (M)2880 s (oil) 1080 (W) 2810 8 (oil) 1055 (M) 1895 (W) 1042 s 1640 (s)1592 s 992 s 1553 (M) 953 V 1502 M 912 (W) 1475 (M) 903 (M) 1458 s (011)867 (M) 1445 (M) (sh) 852 (W) 1426 (M) 842 (W) 1370 (M) (oil) 799 (W)1351 (M) 715 (W) 1306 (M) 704 s) 1276 W 675 (M) 1255 s 658 (\M) 1241 (M)and the following elemental analysis:

Analysis.Calcd. for CHI-114N404: C, H, N, 21.04. Found: C, 49.81; H,5.20; N, 20.92.

9 3 D ribofuranosyl 7 deazaadenine (sparsomycin A) was also isolated andpurified from fermentation broth in another manner. The fermentation wascarried on as described above under A. The whole beer (AJW-63) wasadjusted to pH 2.5 with 365 ml. of concentrated sulfuric acid andfiltered using 6% diatomaceous earth as filter aid. The filter cake waswashed with 0.1 volume of deionized water and the wash added to theclear beer. The clear beer was then adjusted to pH 8.0 with 400 ml. of50% aqueous sodium hydroxide and stirred 1 hour with 1% decolorizingcarbon and 3% diatomite. The mixture was filtered and the carbon cakewashed with 0.1 volume of deionized water followed by 0.2 volume of 20%aqueous acetone. The washed carbon Was eluted twice with 0.4 volume of40% aqueous acetone which had been acidified to pH 2.5 with concentratedsulfuric acid, and the eluates were pooled. The pooled acetone eluateswere then adjusted to pH 4.8 with 53 ml. of 50% aqueous sodiumhydroxide, concentrated to an aqueous solution and freeze-dried to yield284 g. of preparation W'MH-32.6 assaying 9KB ,u../mg. in tissue culture.100 g. of this preparation was then dissolved in 600 ml. of methanol and4 volumes of ether added to precipitate the inactive material. From themethanolether supernatant 2 crops of crystalline material were isolated-by allowing the solvent to evaporate slowly. These preparations werepooled and redissolved .in 35 ml. of water and 5 ml. of 0.1 Nhydrochloric acid. The solution was then filtered and adjusted to pH 9.4with 50% aqueous sodium hydroxide. The sparsomycin A whichseparated incrystalline form was collected, washed 'with water, and dried to give480 mg. of preparation ADA-104.1 having a melting point of 247.8250.8C., an optical rotation [011 -61 (c.=0.90-8 in 0.1 N HCl), an equivalentweight of 270, pKa' of 5.05 in water, and ultraviolet absorptionspectrum in Water 269.5 111,14, a=44.27.

0.01 N H 50 227 mu, a=86.06,

0.01 N KOH 270 m 21:43.61.

a characteristic IR absorption at the following frequencies expressed inreciprocal centimeters:

3400 s 1370 M (011) 3310 s 1355 (s 3240 s 1342 (M) 3220 s 1310 s 3140(s) 1285 (M) 2950 s (oil) 1280 (M) 2920 8 (oil) 1260 s 2850 5 (oil) 1245s 2620 (M) 1200 (M) 1910 (W) 1164 (M) 1650 s 1137 s 1645 s 1125 (M) 1600s 1092 s 1526 s 1084 (M) 1510 (M) 1057 M 1480 s 1045 s 1462 8 (oil) 1020s 1425 s 995 s 955 (M) 8 912 (M) 800 (M) 905 (M) 715 s 870 s 702 s 852W) and the following elemental analysis:

Analysis.-Calcd. for C11H14N4O41 C, H, 5.30; N, 21.04. Found: C, 49.62;H, 5.04; N, 20.81.

The characteristics of sparsomycin A, described above, are in goodagreement with those reported in the literature for tubercidin. SeeAnzai, K,; G. Nakamuna and S. Suzuki; A new antibiotic, tubercidin. J.Antibiotics, Ser. A, pp. 201-204, September 1957. However, no processwhereby tubercidin can be produced is disclosed.

D. 9 (2,3'-O-ISOPROPYLIDE-NE-BD-RIBOFURANOSYL)- 7 DEAZAADENINE;2,3-O-ISOPROPYLIDENESPAR- SOMYCIN A A mixture of 1 g. of sparsomycin Awhich had been dried overnight at 108 C. under a reduced pressure of 0.3mm., 7.5 g. of p-toluenesulfonic acid monohydrate and 50 ml. of acetonewhich previously had been distilled from potassium permanganate andpotassium carbonate in that order, was stirred at room temperature for aperiod of 2 hours. The reaction mixture was then cooled to 3 C. and asolution of 200 ml. of 0.5 N sodium bicarbonate at 3 C. was added. Theresulting solution was evaporated to dryness at 35 C. under reducedpressure. The residue thus obtained was extracted first with two -ml.portions of boiling chloroform and then with two 100-ml. portions ofchloroform at room temperature. These extracts were filteredindividually, then combined and evaporated. The thus-obtained residuewas dissolved in 25 ml. of boiling water and the resulting solution wasfiltered. Refrigeration of the filtrate gave a crystalline precipitateof 2',3' O isopropylidenesparsomycin A weighing 0.75 g. (65%) and havinga melting point of 170-173 C.

After two additional recrystallizations from water, 9-(2',3' Oisopropyl-idene [3 D ribofuranosyl) 7- deazaadenine(2',3'-O-isopropylidenesparsomycin A) (2, 3'-isopropylidenetubercidin)of melting point 174-177 C. was obtained having the following analysis:

Analysis.-Calcd. for C H N O C, 54.89; H, 5.92; N, 18.19; 0, 20.92; CHC, 4.92. Found: C, 54.72; H, 5.92; N, 18.51; 0, 21.2; CH C, 4.3.

TUBERCIDIN To a solution of 1.74 g. of 2'3-0-isopropylidenetubercidin in50 ml. of pyridine in an ice bath was added 4.35 g. of benzoyl chloride.The reaction mixture was stirred in an ice bath for 90 minutes and thenpoured into ml. of ice and water. The mixture was then acidified with 2N hydrochloric acid and filtered. The solid recovered by filtration wasrecrystallized from acetone-water to yield 3.28 g. of material which wasagain recrystallized from acetone-water to yield 2.78 g. of analyticallypure N ,N 5'-tribenzoyl-2',3' O isopropylidenetubercidin having amelting point of 1315-133 C.

Analysis.-Calcd. for C35H31N4O7I C, 67.84; H, 5.04; N, 9.04. Found: C,67.31; H, 5.04; N, 9.13.

To a partial solution of 0.5 g. of N ,N ,5-tribenzoyl-2,3'-O-isopropylidenetubercidin in 50 ml. of a mixture of anhydroustetrahydrofuran and anhydrous methanol (1:1 by volume) in an ice bathwas added with stirring 0.2 ml. of 25% sodium methoxide in methanol. Themixture was removed from the ice bath and the reaction followed by thinlayer chromatography on silica gel with 50% acetone-50% Skellysolve Bhexanes. After 25 minutes at room temperature (about 25 C.) anadditional 0.2 ml. of 25% sodium methoxide was added. After 64 minutesmost of the starting material had disappeared. The reaction mixture wasthen cooled overnight (for about 17 hours) in a refrigerator between andC. and was then acidified to a pH between 5-6 with the aid of an acidexchange resin (Dowex 50-WX8). The solution was then concentrated underreduced pressure (40 45 C.) to yield a syrup which was chromatographedover 50 g. of silica gel with a mixture consisting of 25% acetone-75%Skellysolve B hexanes, taking fractions of 7 ml. each. Fractions 80-115were combined and concentrated to give 210 mg. of N-benzoyl-2',3'-O-isopropyli denetubercidin having the followinganalysis:

Analysis.-Calcd. for C H N O C, 61.30; H, 5.63; N, 13.62. Found: C,61.05; H, 5.64; N, 13.43.

Recrystallized from ether-Skellysolve B hexanes, Nbenzoyl-Z,3-O-isopropylidenetubercidin had a melting point of 106.5109C.

PREPARATION 2 6-methylmercapt0-9- (2',3-O-isopr0pylidene-;3-D-rib0juranosyl) -7-deazapurine' A solution of 6 mercapto 9,8-D-ribofuranosyl-7- deazaadenine (1 g.) in 8 ml. of 0.4 N sodiumhydroxide was shaken at about 24 C. for a period of 10 minutes while0.21 ml. of methyl iodide was added in portions. Another portion of 1.3ml. of 0.4 N sodium hydroxide was added and the solution was shakenagain with 0.21 ml. of methyl iodide. The reaction mixture was allowedto stand for 4 hours at room temperature and thereupon in a refrigeratorovernight for 20 hours at about 0 to 5 C. The solids which separatedwere collected and filtered, dried over sodium hydroxide, refluxed forseveral minutes with 6 ml. of absolute methanol and chilled yieldingwhite needles which were recovered by filtration. The white material was6-methylmercapto-9- 3-D-ribofuranosyl)-7-deazaadenine.

A mixture of 1 g. ofG-methylmercapto-9-;8-D-ribofuranosyl-7-deazaadenine which had beendried overnight at 108 C. under a reduced pressure of 0.3 mm., 7.5 g. ofp-toluenesulfonic acid monohydrate and 50 ml. of acetone whichpreviously had been distilled from potassium permanganate and potassiumcarbonate in that order, was stirred at room temperature for a period of2 hours. The reaction mixture was then cooled to 3 C. under reducedpressure. The residue thus obtained was extracted first with two IOO-ml.portions of boiling chloroform and then with two 100-ml. portions ofchloroform at room temperature. These extracts were filteredindividually, then combined and evaporated. The thusobtained residue wasdissolved in 25 ml. of boiling water and the resulting solution wasfiltered. Refrigeration of the filtrate gave a crystalline precipitateof 6-methylmercapto 9 (2',3' O isopropylidene-p-D-ribofuranosyl)-7-deazapurine.

Substituting in Preparation 2 for methyl iodide another lower alkyliodide, e.g., ethyl iodide, propyl iodide, isopropyl iodide, butyliodide, isobutyl iodide and the like other 6-alkyl mercapto9-(2',3-O-isopropylidene-fi-D- ribofuranosyl)-7-deazapurine compoundsare obtained, such as 6 ethylmercapto-9-(2,3-O-isopropylidene-fl-D-ribofuranosyl)-7-deazapurine, 6 propylmercapto 9-(2',3-O-isopropylidene-B-D-ribofuranosyl) 7 deazapurine;6-isopropylmercapto-9-(2',3-Oisopropylidene-fl-D-ribofuranosyl)-7-deazapurine; 6butylmercapto-9-(2',3-O-isopropylidene-[i-D-ribofuranosyl)-7-deazapurine; 6 isobutylmercapto 9(2',3 O isopropylidene-B-D-ribofuranosyl)-7-deazapurine, and the like.

In the same manner given in Preparation 1D,9-B-D-ribofuranosyl-6-hydroxy-7-deazapurine (or in the keto from 7 fl Dribofuranosyl-7H-pyrrolo[2',3-d]pyrimiclone- 4),9-fi-D-ribofuranosyl-6-mercapto-7-deazapurine, 9-;3-D-ribofuranosyl-6-ethylmercapto-7-deazapurine,9-fi-D-ribofuranosyl-6-butylmercapto-7-deazapurine, 9 fl Dribofuranosyl-7-deazapurine [see I. E. Pike et al., Journal ofHeterocyclic Chemistry I, 159 (1964)] are treated with a ketone, e.g.acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, dibutylketone, cyclopentanone, cyclohexanone cycloheptanone, and the like inthe presence of a benzenesulfonic acid, e.g., p-toluenesulfonic acid, togive the corresponding 2',3'-O-substituted derivative.

PREPARATION 3 N -benz0yl-9- (2,3 '-0-isopropylidene-fi-D-ri b0-furanosyl)-7-deazaadenine 5-phosphate A solution of 12 mmoles of freshlyprepared cyanoethyl phosphate in 12.0 ml. of pyridine was dried byrepeated concentration under reduced pressure at a bath temperature of35, introducing only dry air between additions. After the finalconcentration 2.05 g. (5.0 mmoles) of N benzoyl9-(2',3'-O-isopropylidene- 3-D- ribofuranosyl)-7-deazaadenine was added,followed by ml. of especially dried pyridine. The concentration wasrepeated as above and the residue dissolved in 40 ml. of the samepyridine. Dicyclohexylcarbodiimide (6.19 g., 30 mmoles) was added andthe mixture was shaken in the dark at room temperature for 4 days. Water(4.0 ml.) was added and the mixture was shaken for an additional 30minutes with 40 ml. of water, and filtered. The filtrate wasconcentrated under reduced pressure in a 35 bath to yield a syrup whichwas dissolved in 50 ml. of water and extracted with ether. The aqueouslayer was then lyophilized. Upon dissolving the lyophilized solid inwater, crystallization occurred. The crystals were collected on filterand dried in a vacuum desiccator over anhydrous calcium chlorideyielding 1.43 g. of N -benzo yl-9-(2',3'-O-isopropylidene B Dribofuranosyl) 7- deazaadenine 5'-(2-cyanoethyl phosphate) M.P. 210-222;

A512? 303 m (e 12,000)

A small sample (100 mg.) was recrystallized from 12 ml. methanol and 12ml. water; M.P. 219-220 C.

Analysis.Calcd. for C H N O P: C, 53.03; H, 4.82; N, 12.89; P, 5.70.Found: C, 53.01; H, 4.14; N, 12.47; P, 5.69.

To an ice-cold solution of 544 mg. (1 mmole) N -benzoyl9-(2',3'-O-isopropylidene-B-D-ribofuranosyl)-7-deazaadenine5'-(2-cyanoethyl phosphate) [N -benzoylisopropylidenetubercidin5-(2-cyanoethyl phosphate)] in 5.5 ml. each of water and pyridine wasadded 11.0 ml. of 1.0 N sodium hydroxide. The solution was stirred in anice-bath for 30 minutes and then adjusted to pH 6 with freshly preparedDowex 50-WX8 (pyridinium form). The mixture was filtered, the resinWashed with water, and the combined filtrates lyophilized to yield 500mg. of N benzoyl 9 (2',3 Oisopropylidene-fi-D-ribofuranosyl)-7-deazaadenine 5'-phosphate.

9 PREPARATION v4 9-fi-D-rib0furanos-yl-6-methylmercapt0-7-deazapurine'-ph0sphate In the manner given in Preparation 3,9-(2',3'-O-isopropylidene-fl-D-ribofuranosyl)-6 methylrnercapto 7deazapurine was phosphorylated with Z-cyanoethyl phos phate in thepresence of N,N'-dicyclohexylcarbodiimide. The resulting Z-cyanoethylphosphate was treated with lithium hydroxide and the resulting productwas treated with 1 N aqueous sulfuric acid and finally with bariumhydroxide to give 9-fi-D-ribofuranosyl-6-methylmercapto- 7-deazapurine5-phosphate.

In the same manner given in Preparation 4, other 9-5-D-ribofuranosyl-6-alkylrnercapto-7-deazapurine 5-phosphates can beproduced such as the 9-B-D-ribofuranosyl- 6-ethyl-(6-propyl-,-isopropyl-, -butyl-, isobutyl-)mercapto-7-deazapurine 5'-phosphates.

In the manner given in Preparation 3, other 9-(2',3'-O- isopropylidene BD-ribofuranosyl)-7-deazapurine 5- phosphates are prepared by reactingthe selected 9-(2',3- O-isopropylidene-fi-D-ribofuranosyl)-7-deazapurinewith 2-cyanoethy1 phosphate in the presence of a condensing agent suchas N,N-dicyc1ohexylcarbodiimide and by decomposing with a base theobtained 9-(2',3'-O-isopropylidene-fi-D-ribofuranosyl)-7-deazapurine5-(2-cyanoethylphosphate to obtain the corresponding9-(2,3'-O-isopropylidene ,8 D ribofuranosyl)-7-deazapurine 5- phosphate.Representative compounds thus obtained include: 9(2',3'-O-isopropylidene-B-D-ribofuranosyl)-6- mercapto-7-deazapurine5'-phosphate;9-(2,3-O-isopropylidene-fi-D-ribofuranosyl)-6-hydroxy-7-deazapurine 5'-phosphate; 9- 2',3 -O-isopropylidene-B-D-ribofuranosyl) 7-deazapurine5'-phosphate and the like.

In the manner given in Preparation 1E and IF other Nacyl-9-(2',3'-O-isopropylidene-/3-D-ribofuranosyl)-7- deazaadenines canbe prepared by reacting 9-(2',3'-O-is0-propylidene-fl-D-ribofuranosyl)-7-deazaadenine with an acid chloride oracid anhydride and reacting the resulting material with a base, e.g.,sodium or potassium methoxide or ethoxide. Representative compounds thusobtained include: N -acetyl-9-(2,3-O-isopropylidene-B-D- ribofuranosyl)-7-deazaadenine N -propiony1-9-(2',3'-O- isopropylidene {3D-ribofuranosyl)-7-deazaadenine; N butyryl 9(2'3'-O-isopropylidene-B-D-ribofuranosyl)-7- deazaadenine; Nvaleryl-9-(2',3'-O-isopropylidene-;3-D- ribofuranosyl)-7-deazaadenine; Nhexanoyl-9-(2',3-O isopropylidene-fi-D-ribofuranosyl) -7-deazaadenine) Nphenylacetyl 9(2',3-O-isopropylidene-fl-D-ribofuranosyl)-7-deazaadenine; N-phenylpropionyl-9-(2',3'-O-isopropylidene-B-D-ribofuranosyl)-7-deazaadenine;N decanoyl-9-(2',3'-O-isopropylidene B-D-ribofuranosyl)-7- deazaadenine;N -lauroyl-9-(2',3'-O-isopropylidene- 8-D-ribofuranosyl)-7-deazaadenine; N -anisoy1-9-(2,3'-O-isopropylidenefl-D-ribofuranosyl)-7-deazaadenine; N -(,8 cyclopentylpropionyl) 9(2',3-O-isopropy1idene ,B-D- ribofuranosyl)-7-deazaadenine, and thelike, which likewise as in Preparation 3 are converted to thecorrespondin; phosphate, such as N -acetyl-9-(2',3'-O-isopropylidene-B-D-ribofuranosyl) 7 deazaadenine 5'-phosphate; N propionyl9-(2,3'-O-isopropylidene-p-D-ribofuranosyl)-7-deazaadenine 5'-phosphate;N -butyryl-9-(2',3'- O-isopropylidene-B-D-ribofuranosyl)-7-deazaadenine5'- phosphate; N-valeryl-9-(2,3'-O-isopropylidene-/3-D-ribofuranosyl)-7-deazaadenine5-phosphate; N -hexanoyl-9- (2.,3O-isopropylidene-[i-D-ribofuranosyl)-7-deazaadenine 5-phosphate; N-phenylacetyl-9-(2',3'-isopropylidene-fl-D-ribofuranosyl)-7-deazaadenine5' phosphate; N -phenylpropionyl-9-(2',3'-O-isopropylidene-B-Dribofuranosyl)-7-deazaadenine 5'-phosphate; N -decanoyl-9-(2',3-O-isopropylidene-B-D-ribofuranosyl) 7-deazaadenine 5-phosphate; N-lauroyl-9-(2,3'-O-isopropylidene- B-D-ribofuranosyl)-7-deazaadenine5-phosphate; N -anisoyl 9-(2',3' O isopropylidene-B-D-ribofuranosyl)-7-deazaadenine 5'-phosphate; N cyclopentylpropionyl-9-(2.,3'-O-isopropylidene-fl-D-ribofuranosyl) 7-deazaadenine 5'-phosphateand the like.

EXAMPLE 1 Methyl N -benz0yl-9-(2,3'-O-isopropylidene-firibofuranosyl)-7-a'eazaadenine 5-ph0sphate A solution of 0.5 mrnole of N-benzoyl-9-(2',3-0-isopropylidene-B-D-ribofuranosyl)-7-deazaadenine5'-phosphate and 12 ml. of anhydrous pyridine [purified according toJacob and Khorana, J. Am. Chem. Soc., 86, 1630 (1963)] was dried bydistillation of the pyridine under reduced pressure. Pyridine was addedand the solution again was concentrated to dryness under reducedpressure. This was repeated twice more and thereupon the resultantproduct was dissolved in 10 ml. of the same pyridine under anhydrousconditions and to this solution was added 2.6 ml. of tri-n-butyl amine,20 ml. of anhydrous methanol and 7 g. of dicyclohexylcarbodiimide. Themixture was stirred at room temperature (24 to 26 C.) in the dark for 41hours and then concentrated to a small volume under reduced pressure. Tothis small volume were added 2 volumes of ether and the ether layerdecanted. More ether was added and the mixture was filtered. The solidscollected on filter were mixed with 25 ml. of Water and this mixture wasstirred for 2 hours. The mixture was then filtered and the filtrateallowed to stand for a period of 3 hours and again filtered. Thethusobtained solution showed 3400 optical density units (O.D.U.) at 302mg. The e of the starting material was 9200, therefore 74% ofesterification was achieved. The aqueous layer was then concentrated todryness to give N benzoyl 9 (2,3'-O-isopropylidene-,8-Dribofuranosyl)-7-deazaadenine 5'-methylphosphate.

EXAMPLE 2 Methyl 9-fi-D-ribofuran0syl-7-deazaudenine 5'-phosphate(methyles ter of Sparsomycin A 5'-ph0sphate) solvent consisting ofisopropionyl, concentrated ammo-' nium hydroxide and water in a ratio of7:1:2 and chromatographed (4 ml. fractions) on 35 g. of silica gel, previously charged with the same solvent mixture. Fractions 22-30 werecombined and the ultraviolet spectrum determined; total 0.D.U.=1938 at269 m The fractions 22-30 were concentrated and finally lyophilized togive methyl 9-fl-D-ribofuranosyl-7-deazaadenine 5-phosphate as a Whitesolid, R =0.50.

EXAMPLE 3 Ethyl ester of9-(2',3-O-is0pr0pylidene-,B-D-rib0furanosyl)-7-deazapurine 5'-ph0sphateIn the manner given in Example 1,9-(2',3-O-isopropylidene-,8-D-ribofuranosyl) 7 deazapurine 5-phos phatein pyridine solution was reacted under anhydrous conditions withtriethylamine, ethanol, and dicylcohexyl carbodiimide to give the ethylester of 9-(2,3-O-isopropylidene D ribofuranosyl)-7-deazapurine 5'-phosphate.

. EXAMPLE 4 Ethyl ester of 9-[3-D-rib0furanosyl-7-deazapurine5'-ph0sphate The ethyl ester of9-(2',3'-O-isopropylidene-fl-D-ribofuranosyl)-7-deazapurine 5'-phosphateobtained as in Ex- 11 ample 3 was hydrolyzed with 80% aqueous aceticacid like in Example 2 to give the ethyl ester of9-;8-D-ribofuranosyl-7-deazapurine 5-phosphate.

EXAMPLE 5 Butyl ester of 9- 2 ',3 O-isopropy lz'dene-,B-D-rib0furan0-syl) -7-deazapurine 5 -phosphate In the manner given in Example 1,9-(2',3'-O-isopropylidene-fi-D-ribofuranosyl)-7-deazapurine 5'-phosphatein pyridine solution was reacted under anhydrous conditions withtriethylamine, butanol and dicyclohexyl carbodiimide to give the butylester of 9-(2',3-O-isopropylidenefi-D-ribofuranosyl)-7-dcazapurine5'-phosphate.

EXAMPLE 6 Butyl ester of 9-fi-D-rib0furan0syl-7-deazapuri1ze5'-ph0sphate The butyl ester of9-(2',3-O-isopropylidene-fi-D-ribofuranosyl)-7-deazapurine 5-ph0sphate,obtained as in EX- ample 5, was hydrolyzed with 80% aqueous acetic acidlike in Example 2, to give the butyl ester of9-,B-D-ribofuranosyl-7-deazapurine 5-phosphate.

EXAMPLE 7 Hexyl ester of9-(2,3-O-is0pr0pylidene-fi-D-ribofuranosyl)-7-deazapurine 5-pl10sphateIn the manner given in Example 1,9-(2',3'-O-isopropylidene-fi-D-ribofuranosyl)-7-deazapurine 5 phosphatein pyridine solution was reacted under anhydrous conditions withtriethylamine, hexanol and dicyclohexylcarbodiimide to give the hexylester of 9-(2',3'-O-isopropylidene-,B-D-ribofuranosyl)-7-deazapurine 5'phosphate.

EXAMPLE 8 Hexyl ester of 9-,8-D-rib0furan0syl-7-deazapurine 5-ph0splzateThe hexyl ester of9-(2,3-O-is-opropylidene-;8-D-ribofuranosyl)-7-deazapurine 5'-phosphate,obtained as in EX- ample 7, was hydrolyzed with 80% aqueous acetic acidlike in Example 2 to give the hexyl ester of9-5-D-ribofuranosyl-7-deazapurine 5-phosphate.

EXAMPLE 9 EXAMPLE 11 Methyl ester of9-(2',3'-O-is0pr0pylidene-[S-D-ribofztranosyl)-6-mercapt0-7-deazapw'ine5'-ph0sphate In the manner given in Example 1,9-(2',3-O-isopropylidene-,B-D-ribofuransyl)-6-mercapto 7 deazapurine-phosphate in pyridine solution was reacted under anhydrous conditionswith triethylamine, methanol and dicyclohexylcarbodiimide to give themethyl ester of 9-(2,3' O isopropylidene t3 D ribofuranosyl)-6-mercapt0-7-deazapurine 5'-ph0sphate.

EXAMPLE 12 Methyl ester of 9-fi-D-rib0furan0syl-6-mereapto-7-deazapurine 5-ph0spl1ate The methyl ester of9-(2',3'-O-isopropylidene-fi-D- ribofuranosyl) 6 mercapto 7 deazapurine5-phosphate, obtained as in Example 11, was hydrolyzed with aqueousacetic acid like in Example 2, to give the methyl ester of9-,B-D-ribofuranosyl-6-mercapto-7-deazapurine 5-phosphate.

EXAMPLE 13 Propyl ester of9-(2',3-0-is0pr0pylidene-fi-D-ribofuranosyl)-6-methylmercapt0-7-deazapurine5'-ph0sphate In the manner given in Example 1, 9-(2',3'-O-isopropylideneB D ribofuranosyl)-6-methylmercapto-7- deazapurine 5'-phosphate inpyridine solution was reacted under anhydrous conditions withtriethylamine, propanol and dicyclohexylcarbodiimide to give the propylester of 9 (2,3 O isopropylidene 3 D ribofuranosyl)-6-methylmercapto-7-deazapurine 5-phosphate.

EXAMPLE 14 Propyl ester of 9-fi-D-rib0furan0syl-6-methylmercapto-7-a'eazapurine 5-ph0sp/zate The propyl ester of 9(2',3-O-isopropylidene-{3-D- ribofuranosyl) 6 methylmercapto 7deazapurine 5'- phosphate obtained as in Example 13, was hydrolyzed with80% aqueous acetic acid like in Example 2, to give the propyl ester of9-fi-D-ribofuranosyl-6'methylmercapto-7-deazapurine 5-phosphate.

EXAMPLE 15 Pentyl ester of 9-(2',3'-O-is0pr0pylidene-{B-D-ribofuranosyl)-6-ethylmerczipt0-7-deazapurine 5 -p/z0splzate In the manner given inExample 1, 9-(2,3-O-isopropylidene t? Dribofuranosyl)-6-ethylmercapto-7- deazapurine 5-phosphate in pyridinesolution was reacted under anhydrous conditions with triethylamine,pentanol and dicyclohexylcarbodiimide to give the pentyl ester of 9(2',3 O isopropylidene B D ribofuranosyl)-6- ethylmercapto-7-deazapurine5 -phosphate.

EXAMPLE 16 Pentyl ester of 9-;3-D-ribofuranosyl-6-ethylmereapto-7-deazapurine 5-ph0spl1ate The pentyl ester of9-(2,3-O-isopropylidene-[i-D-ribofuranosyl) 6 ethylmercapto 7deazapurine 5'-ph0sphate, obtained as in Example 15, was hydrolyzed with80% aqueous acetic acid like in Example 2, to give the pentyl ester of9-,8-D-ribofuranosyl-6-ethylmercapto-7- deazapurine 5'-ph0sphate.

EXAMPLE 17 Phenyl ester of9-(2,3'-O-is0pr0pylidene-B-D-ribofuranosyl)-7-deazapurine 5-ph0sphate Inthe manner given in Example 1, 9-(2',3'-O-is0-propoylidene-fi-D-ribofuranosyl) 7 deazapurine 5-phosphate in pyridinesolution was reacted under anhydrous conditions with triethylamine,phenol and dicyclohexylcarbodiimide to give the phenyl ester of9-(2,3'-O-isopropylidene [3 D ribofuranosyl)-7-deazapurine 5- phosphate.

EXAMPLE 18 Phenyl ester of 9-fi-D-rib0furan0syl-7-deazapurine 5'-phosphate The phenyl ester of9-(2,3'-O-isopropylidene-fl-D-ribofuranosyl)-7-deazapurine 5'-phosphate,obtained as in Example 17, was hydrolyzed with 80% acetic acid like inExample 2, to give the phenyl ester of9-;8-D-ribofuranosyl-7-deazapurine 5-phosphate.

13 EXAMPLE 19 Methyl ester9-(2',3'-O-isopropylidene-/3-D-rib0furanosyl)-6-hydroxy-7-deazapurine'-phosphate In the manner given in Example 1,9-(2',3-O-isopr0pylidene-fi-D-ribofuranosyl) 6 hydroxy-7-deazapurine 5'-phosphate in pyridine solution was reacted under anhydrous conditionswith triethylamine, methanol and dicyclohexylcarbodiimide to give themethyl ester of 9-(2', 3'-O-isopropylidene B D ribofuranosyl) 6-hydroxy-7-deazapurine 5-phosphate.

EXAMPLE 20 Methyl ester of 9-fi-D-ribofuran0syl-6-hydr0xy- 7-deazqpurine5 '-phosphate The methyl ester of 9-(2'-,3'-O-isopropylidene-ti-D-ribofuranosyl) 6 hydroxy-7-deazapurine 5'-phosphate, obtained as inExample 19,-was hydrolyzed with 80% aqueous acetic acid, like in Example2, to give the methyl ester of 9 5 Dribofuranosyl-6-hydroxy-7-deazapurine 5-phosphate.

EXAMPLE 21 Cyclopentyl ester of 9 (2'3'-O-is0pr0pylidene-BD-ribofuranosyl)-7-deazapurine 5 '-phosphate In the manner given inExample 1, 9,-(2',3'-O-isopropylidene-fi-D-ribofuranosyl) 7-deazapur ine5'-phosphate in pyridine solution was reacted under anhydrous conditionswith triethylamine, cyclopentanol and dicyclohexylcarbodiimide to givethe cyclopentyl ester of 9-(2',3'-O- isopropylidene 13 D-ribofuranosyl)7 deazapurine 5'- phosphate. 2

EXAMPLE 22 cyclopentyl ester of 9- 8-D-ribofurano-syl- 7-deazapurine5'-ph0sph zte The cyclopentyl ester of 9-(2,3 O-isopropylidene-B-D-nbofuranosyl)-7-deazapurine 5-phosphate, obtained as in Example 21,washydrolyzed with 80% aqueous acetic' acid like in Example 2, to givethe cyclopentyl ester of 9-[3-D-ribofuranosyl-7-deazapurine Sfhosphate.

EXAMPLE 23 Cyclohexyl ester of 9-(2',3-O-is0pr0pylidene-fl-D-ribofuranosyl) -7-deazapurirze 5',-ph0sphate In the manner given inExample 1, 9-(2',3-O-isopropylidene-fl-D-ribofuranosyl)-7-deazapurine5'-phosphate in pyridine solution was reacted under anhydrous conditionswith triethylamine, cyclohexanol and dicyclohexylcarbodiimide to givethe cyclohexyl ester of 9-(2',3'-O- isopropylidene8-D-ribofuranosyl-7-deazapurine 5'-phosphate.

EXAMPLE 24 Cyclohexyl ester of 9-,8-D-ribqfuranosyl- 7-deazapurine5'-ph0sp'hate The cyclohexyl ester of 9-(2',3'-O-isopropy1idene-;8-D-

ribofuranosyl)-7-deazapurine 5'-phosphate, obtained as in Example 23,was hydrolyzed with 80% aqueous acetic acid like in Example 2, to givethe cyclohexyl ester of 9-B-D-ribofuranosyl-7-deazapurine 5-phosphate.

EXAMPLE 25 Ethyl ester of N -lauroyl-9-(2',3'-O-isopr0pylidene-B-D-ribofuranosyl) -7-deqzaadenin; 5 '-phosphate In the manner given inExample 1, N -lauroy1-9-(2',3- O-isopropyldiene-fi-D-ribofuranosyl)-7deazaadenine 5'- phosphate in pyridine solution was reacted underanhydrous conditions with tributylamine, ethanol anddicyclohexylcarbodiimide to give the ethyl ester of N -lauroyl-9-(2',3'-O-isopropylidene-/3-D-ribofuranosyl) 7 deazaadenine5'-phosphate.

EXAMPLE 26 Ethyl ester of 9-fl-D-ribofuranosyl-7-deazaadenine5-ph0sph'ate In the manner given in Example 2, the ethyl ester of N-lauroyl 9-(2,3'-O-isopropylidene p D ri-bofuranosyl)-7-deazapurine5'-phosphate, obtained as in Example 25, was hydrolyzed first withconcentrated ammonium hydroxide in methanol and then with aqueous aceticacid to give the ethyl ester of 9-5-D-rib0furanosyl-7- deazaadenine5'-phosphate.

EXAMPLE 27 2,4-dinitr0phenylester of N-acetyl-9-(2',3'-0-is0pr0pylidene-fi-D-ribofuranos'yl) -7-deazaadenine 5-phosphate In the manner given in Example 1, N -acetyl-9-(2',3'-O-isopropylidene-fi-D-ribofuranosyl) 7-deazaadenine 5'- phosphate inpyridine solution was reacted under anhydrous conditions withtributylamine, 2,4-dinitropheno1 and dicyclohexylcarbodiimide to givethe 2,4-dinitrophenyl ester of N -acetyl 9(2',3'-O-isopropylidene-B-D-ribofuranosyl)-7-deazaadenine 5'-phosphate.

EXAMPLE 28 2,4-dinitr0phenylester of 9-B-D-ribofuran0syl- 7-deazaadenine5 -phosphate In the manner given in Example 2, the 2,4-dinitrophenylester of N -acetyl-9-(2',3'-O-isopropylidene B Dribofuranosyl)-7-deazaadenine 5-phosphate, obtained as in Example 27,was hydrolyzed first with concentrated ammonium hydroxide in methanoland then with 80% aqueous acetic acid to give the 2,4-dinitrophenylester of 9-,B-D- ribofuranosyl-7-deazaadenine-5-phosphate.

EXAMPLE 29 Z-naphthyl ester of N -acetyI-Q-(2',3'-0-is0pr0pylidene-.B-D-ribofuranosyl) -7-deazaaden ine 5 -phosphate In the manner given inExample 1, N -acetyl-9-(2,3'- O-isopropylidene B Dribofuranosyl)-7-deazaadenine 5-phosphate in pyridine solution wasreacted under anhydrous conditions with tributylamine, Z-naphthol anddicyclohexylcarbodiimide to give the 2-naphthyl ester of N -acetyl9-(2',3'-O-is0propylidene 3 D ribofuranosyl)-7-deazaadenine 5-phosphate.

EXAMPLE 3O Z-naphthyl ester of 9-B-D-ribofuranosyl- 7-deazaadenine 5'-phosphate In the manner given in Example 2, the 2-naphthy1 ester of Nacetyl 9 (2',3'-O-isopropylidene-/3-D-ribofuranosyI)-7-deazaadenine5-phosphate, obtained as in Example 29, was hydrolyzed first withconcentrated ammonium hydroxide in methanol and then with 80% aqueousacetic acid to give the Z-naphthyl ester of 9-fl-D-ribofuranosyl-7-deazaadenine 5'-phosphate.

EXAMPLE 31 'Methyl ester of N -benzoyl-9-B-D-rib0furan0syl-7-deazaadenine 5'-ph0sphate hydrolyzing this ester with an acid toobtain the corresponding nucleoside alkyl or aryl '-phosphate ester. Ifin addition acyl groups attached to amides are to be removed, a basehydrolysis, e.g. with ammonium hydroxide in methanol, is necessary.Representative compounds thus obtained include: the 4-nitronaphthylester of 9-fi-D- ribofuranosyl-7-deazapurine 5'-phosphate; the decylester of 9-[i-D-ribofuranosyl-6-hydroxy-7-deazapurine 5-phosphate; theoctyl ester of 9-B-D-ribofuransoyl-6-mercapto- 7-deazapurine5'-phosphate; the hexyl ester of 9-B-D-ribofuranosyl6-butylmercapto-7-deazapurine 5-phosphate; the butyl ester of9-B-D-ribofuranosyl-6-hydroxy-7-deazapurine 5'-phosphate; thep-nitrophenyl ester of N -acetyl- 9-fi-D-ribofuranosyl-7-deazaadenine5'-phosphate; the 1- naphthyl ester of N-phenylacetyl-9-fl-D-rib0furanosyl-7- deazaadenine 5-phosphate; thep-tolyl ester of 9-,8-D- ribofuranosyl-6-propylmercapto-7-deazapurine 5'phosphate; the S-methylnaphthyl ester of N-lauroyl-p-D-ribofuranosyl-7-deazaadenine 5-phosphate; the5,8-dimethylnaphthyl ester of 9-B-D-ribofuran0syl 7-deazapurine 5'-phosphate; the cyclodecyl ester of N-anisoyl-9-fi-D-ribofuranosyl-7-deazaadenine 5-phosphate and the like.

We claim:

1. A compound selected from alkyl, cycloalkyl and aryl esters of a9-[3-D-ribofuranosyl-7-deazapurine 5- phospshate having the formula:

wherein Z is selected from the group consisting of hydrogen, hydroxy,amino, acylamino, in which the acyl group is of a hydrocarbon carboxylicacid containing from 2 to 12 carbon atoms, inclusive, and anisoyl, thioand alkylthio in which the alkyl group has from 1 to 4 carbon atoms,inclusive, and wherein R is selected from the group consisting of alkylradicals having from 1 to 12 carbon atoms, cycloalkyl radicals havingfrom 5 to 10 carbon atoms and aryl having from 6 to 12 carbon atoms,inclusive.

2. The methyl ester of 9-B-D-ribofuranosyl-7-deazaadenine 5'-phosphate.

3. The methyl ester of N -benzoyl-9-,6-D-ribofuranosyl- 7-deazaadenine5'-phosphate.

4. The ethyl ester of 9-fi-D-ribofuranosyl-7-deazapurine 5-phosphate.

5. The methyl ester of 9-;8-D-ribofuranosyl-6-mercapto- 7-deazapurine5'-phosphate.

6. A compound selected from alkyl, cycloalkyl and aryl esters of a9-(2,3'-substituted-,B-Dribofuranosyl)-7- deazapurine 5 '-phosphate ofthe formula:

wherein R and R are alkyl radicals having from 1 to 4 carbon atoms,inclusive or together can form an alkylene chain of 4 to 6 carbon atoms,inclusive, wherein Z is selected from the group consisting of hydrogen,hydroxy, amino, acylamino, in which the acyl group is of a hydrocarboncarboxylic acid containing from 2 to 12 carbon atoms, inclusive, andanisoyl, thio and alkylthio in which the alkyl group has from 1 to 4carbon atoms, inclusive, and wherein R is selected from the groupconsisting of alkyl radicals having from 1 to 12 carbon atoms,cycloalkyl radicals having from 5 to 10 carbon atoms and aryl havingfrom 6 to 12 carbon atoms, inclusive.

7. The methyl ester of N-benzoyl-9-(2',3',O-isopropylidene-B-D-ribofuranosyl)-7-deazaadenine 5'-phosphate.

8. Ethyl ester of9-(2',3-O-isopropylidene-B-D-ribofuranosyl)-7-deazapurine 5'-phosphate.

9. Methyl ester of 9-(2,3'-O-isopropylidene-fi-D-ribofuranosyl)-6-rnercapto-7-deazapurine 5-phosphate.

References Cited UNITED STATES PATENTS 3,170,835 2/1965 Godfrey 2609783,284,440 11/1966 Patchett et a1 260--21 1.5 3,300,479 1/1967 Hanze260-2115 OTHER REFERENCES Khorana: Some Recent Developments in theChemistry of Phosphate Esters of Biological Interest, 1961, pp. 75, 76,99, and106, John Wiley and Sons, Inc., New York, NY.

LEWIS GOTIS, Primary Examiner. I. R. BROWN, Assistant Examiner.

1. A COMPOUND SELECTED FROM ALKYL, CYCLOALKYL AND ARYL ESTERS OF A9-B-D-RIBOFURANOSYL-7-DEAZAPURINE 5''PHOSPSHATE HAVING THE FORMULA: